[TextField] Fix the issue that menu items gets filtered after recreation

It's actually a bug of framework's AutoCompleteTextView. When restoring the
state, it always filters the item list regardless the previously input item
is from menu selection or manual input.

This change fixes the issue by implementing the custom logic of input text
saving/restoring, and properly remember if the last input text filters the
item list or not.

Resolves #1464

PiperOrigin-RevId: 716328564

Author: drchen

lib/java/com/google/android/material/textfield/MaterialAutoCompleteTextView.java

@@ -29,9 +29,14 @@
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.RippleDrawable;
+import android.os.Parcel;
+import android.os.Parcelable;
 import androidx.appcompat.widget.AppCompatAutoCompleteTextView;
 import androidx.appcompat.widget.ListPopupWindow;
+import android.text.Editable;
 import android.text.InputType;
+import android.text.TextUtils;
+import android.text.TextWatcher;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.View.MeasureSpec;
@@ -83,6 +88,8 @@ public class MaterialAutoCompleteTextView extends AppCompatAutoCompleteTextView
   private int simpleItemSelectedColor;
   @Nullable private ColorStateList simpleItemSelectedRippleColor;
 
+  @Nullable private CharSequence selectedItem;
+
   public MaterialAutoCompleteTextView(@NonNull Context context) {
     this(context, null);
   }
@@ -181,6 +188,23 @@ public void onItemClick(AdapterView<?> parent, View selectedView, int position,
     }
 
     attributes.recycle();
+
+    // TODO: Remove this workaround once the framework bug (b/202873898) is fixed.
+    addTextChangedListener(
+        new TextWatcher() {
+          @Override
+          public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
+
+          @Override
+          public void onTextChanged(CharSequence s, int start, int before, int count) {}
+
+          @Override
+          public void afterTextChanged(Editable s) {
+            if (!TextUtils.equals(selectedItem, s)) {
+              selectedItem = null;
+            }
+          }
+        });
   }
 
   @Override
@@ -437,6 +461,55 @@ public CharSequence getHint() {
     return super.getHint();
   }
 
+  @Override
+  public boolean getFreezesText() {
+    // Always return false to handle the input text restoration by ourselves. This is required
+    // to avoid the auto-completion from being updated when the view is recreated.
+    return false;
+  }
+
+  @Override
+  protected void replaceText(CharSequence text) {
+    selectedItem = text;
+    super.replaceText(text);
+  }
+
+  @Override
+  public void setText(CharSequence text, boolean filter) {
+    if (!filter) {
+      // When filter is false, the text is updated by the selection from the auto-complete list.
+      selectedItem = text;
+    }
+    super.setText(text, filter);
+  }
+
+  @Override
+  @NonNull
+  public Parcelable onSaveInstanceState() {
+    Parcelable parcelable = super.onSaveInstanceState();
+    if (TextUtils.isEmpty(getText()) || !super.getFreezesText()) {
+      return parcelable;
+    }
+
+    SavedState savedState = new SavedState(parcelable);
+    // Remember if the current text is from the auto-complete selection.
+    savedState.shouldRefreshAutoCompletion = (selectedItem == null);
+    savedState.inputText = getText();
+    return savedState;
+  }
+
+  @Override
+  public void onRestoreInstanceState(Parcelable state) {
+    if (!(state instanceof SavedState)) {
+      super.onRestoreInstanceState(state);
+      return;
+    }
+
+    SavedState savedState = (SavedState) state;
+    setText(savedState.inputText, savedState.shouldRefreshAutoCompletion);
+    super.onRestoreInstanceState(savedState.getSuperState());
+  }
+
   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
     super.onMeasure(widthMeasureSpec, heightMeasureSpec);
@@ -622,4 +695,40 @@ private boolean hasSelectedRippleColor() {
       return simpleItemSelectedRippleColor != null;
     }
   }
+
+  private static final class SavedState extends BaseSavedState {
+
+    private boolean shouldRefreshAutoCompletion;
+    private CharSequence inputText;
+
+    public SavedState(Parcelable superState) {
+      super(superState);
+    }
+
+    public SavedState(Parcel source) {
+      super(source);
+      shouldRefreshAutoCompletion = source.readInt() != 0;
+      inputText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(source);
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+      super.writeToParcel(out, flags);
+      out.writeInt(shouldRefreshAutoCompletion ? 1 : 0);
+      TextUtils.writeToParcel(inputText, out, flags);
+    }
+
+    public static final Creator<SavedState> CREATOR =
+        new Creator<SavedState>() {
+          @Override
+          public SavedState createFromParcel(Parcel source) {
+            return new SavedState(source);
+          }
+
+          @Override
+          public SavedState[] newArray(int size) {
+            return new SavedState[size];
+          }
+        };
+  }
 }